IBP banding data system: Internal maintenance specification

This class inherits from FieldItem, but it doesn't have a .scanField() method, because the band size comes from the compiler's PageHeader object.

# - - - - -   c l a s s   B a n d S i z e F i e l d   - - - - -

class BandSizeField(FieldItem):
    '''Represents a band size from the page header.

      Exports: as inherited.
    '''

# - - -   B a n d S i z e F i e l d . f l a t t e n   - - -

    @staticmethod
    def flatten(bandSizeField):
        '''Flatten a band size field.
        '''
        if  bandSizeField is None:
            return BLANK_BAND_SIZE
        else:
            return bandSizeField.value.ljust(BAND_SIZE_L)